Mobile crane



Oct. 3, 1967 J. v. M. DEBONA 3,344,931

MOBILE CRANE Filed Jan. 24, 1966 2 Sheets-Sheet 1' 34 26 36 INVENTOR.

OHN ,v. M. DEBON BY L ATTORNEYS Oct. 3, 1967 J. v. M. DEBONA 3,344,931

MOBILE CRANE Filed Jan. 24, 1966 2 Sheets-Sheet 2 INVENTOR. JOHN V. M. DEBONA ATTORNEYS fl BY United States Patent 3,344,931 MOBILE CRANE John V. M. Debona, Orchard Lake, Mich., assrgnor to Darin & Armstrong, Inc., Detroit, Mich., a corporation of Michigan Filed Jan. 24, 1966, Ser. No. 522,629 8 Claims. (Cl. 212-8) ABSTRACT OF THE DISCLOSURE A mobile crane comprising a truck, a crane chassis pivotally connected to the truck at one end thereof, a crane pivotally connected to and extending upwardly from the chassis and an extensible link pivoted at opposite ends to the truck and crane whereby the versatility and load carrying capacity of a fork lift truck may be increased.

In the past load carrying capacities of fork lift trucks or the like have been limited to the weight limitation of the front axle of the fork lift truck and the necessity to prevent pivoting of the fork lift truck about the front axle on lifting of a load. The usual lifting cylinder in fork lift trucks is of sufficient capacity to lift considerably more load than the front axle and pivotal movement of the truck will allow.

In addition, in the past the versatiity of fork lift truckshas been limited due to the usual method of lifting with the truck by means of forks extending forwardly therefrom which are raised vertically on a mast It would therefore be desirable to modify a fork lift truck to provide a more versatile mobile crane having improved lifting and moving versatility and capacity.

In view of the above one of the objects of the present invention is to provide improved mobile crane structure.

Another object of the invention is to provide a wheel driven mobile crane capable of walking a load over uneven terrain.

A further object is to provide a mobile crane with crane support structure which is removable from the ground when the crane is not in use to facilitate maneuvering and rapid transport of the crane.

A still further object is to provide a crane unit for assembly to a drive truck so as to form a mobile crane capable of lifting and supporting greater loads than the usual fork lift truck.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating a preferred embodiment of the invention, wherein:

FIGURE 1 is a side view of a mobile crane according to the invention;

FIGURE 2 is a front view of the crane taken in the direction of arrow 2 in FIGURE 1;

FIGURE 3 is atop view of the crane taken in the direction of arrow 3 in FIGURE 1;

FIGURE 4 is an enlarged view of a portion of FIGURE 1 with the wheels illustrated in phantom;

FIGURE 5 is an enlarged sectional view taken along line 5-5 of FIGURE 1;

FIGURE 6 is a sectional view taken along line 66 of FIGURE 5; and

FIGURE 7 is a sectional view taken along line 77 of FIGURE 4.

As shown in the drawings, a mobile crane according to the invention includes a self-powered truck 10 having drive wheels 12 at one end thereof and steering wheels 14 at the other end. A power winch 16 is mounted on the truck above the steering wheels 14. A suitable engine and transmission in the truck 10 drive the wheels 12 through axle and differential assembly 24.

A crane unit including crane 18 and a crane support chassis 20 is connected to the front of the truck 10. Chassis 20 includes paired plates 26 and 28 as shown best in FIGURES 2 and 7. Plates 28 are seucred together by weld plate 30 and by crane support shaft 32. Crane support wheels 22 are carried by axle 34 which is mounted in blocks 36 carried between the paired chassis plate 26 and 28. Chassis 20 is pivoted to flanges 38 carried by truck 10 at 40 to allow rotation of the chassis relative to the truck about an axis parallel to that axle and differential assembly 24.

The crane 18 includes a support 50 which telescopically houses a mast 52. The support includes vertically extending side Walls 54 secured together by base plate 56 at the lower end thereof and by means 58 extending around the outside of the support at the upper end thereof. U-shaped guide rails 60 are secured to the inside of side walls 54 and fit within the U-shaped mast beams 62.

Beams 62 are joined together at the upperends thereof by'structural member 64. A cable roller 66 is provided at the top of the mast 52. Boom 68 is mounted on mast 52 by an adjustable pin and link connection 70, 72.

Hydraulic lift power cylinder 74 is mounted on support base plate 56 and the piston rod 76 thereof is secured to the structural member 64 so that the mast 52 may be raised and lowered relative to the support 50 by operation of the power cylinder. A cable 78 is wrapped around the reel of winch 16 and runs therefrom over the roller 66 on top of the mast 52 and over boom pulleys 79 to block 80 of block and tackle lift structure carried at the outer end of the boom 68.

The crane 18 is supported by the chassis 20. The lower ends of the support side walls 54 are journaled on the support shaft 32 so that the crane is rotatably mounted. Hydraulic power cylinders 82 are pivotally connected to flanges 84 and 86 carried by the truck 10 and support 50 respectively and are extendable to pivot the crane about shaft 32 as desired.

When in use, the mobile crane is positioned adjacent the object to be lifted and the power cylinders 82 may be adjusted to pivot the crane about shaft 32 so that the block 80 is immediately above the load. Power cylinder 74 may be adjusted to raise or lower mast 52 so that the desired lift can be obtained. The block 80 is then lowered for engagement with the load by unwinding the cable 78 from winch 16. After the load has been lifted by winding in cable 78, the mobile crane may be driven to the desired position for unloading.

The lifting and carrying capacity of a mobile crane according to the invention is larger than the comparable conventional lift truck. This is due in part to the crane support used whereby the load is carried by both truck drive wheels 12 and crane support wheels 22. When the crane is driven with a load the pivot joint connection between the crane chassis 20 and the truck 10 allows the chassis 20 to rotate relative to the truck so that both drive 'wheels 12 and support wheels 22 are in constant contact with the ground. The rocking of the chassis 20 due to ground unevenness raises and lowers the crane unit 18 a smaller amount insuificient to affect cane stability.

When the crane is unloaded the support wheels be lifted up out of contact with the ground so that the mobility of the crane is increased. This is done by first securing the bloc-k 80 to the boom 68, support 50, or chassis 20 and then rotating the winch 16 so that the cable 78 is tightened and the crane, as shown in FIGURE 1, is rotated in a compound counterclockwise direction about the link connections with the truck 10. This movement of the crane pivots the chassis 20 upwardly about 22 may pivot joint 40 so that the support wheels 22 are raised above ground level. When the crane is in the raised position the truck 10 has an increased mobility comparable to that of a conventional fork lift type truck and is easily maneuverable into position to pick up a load.

In addition with: the mobile crane structure of the in-- vention the crane 18 may be disconnected from the cylinders 82 at the crane end of the cylinders 82 and the crane 18 pivoted forward about the: shaft 32- by means of unwinding the cable 78 from the reel of which 16. With the crane 18 in this forward position movement of the mobile crane under low objects, such as door openings or the like, is easily accomplished. Such positioning of the crane 18 also facilitates transporting of the mobile crane on larger trucks or the like where overhead clear woe is restricted. The crane 18 may of course be readily returned to its vertical position by rewinding of the cable 78 and it may be placed in condition for lifting and moving operations by re-connecting of the cylinders 82.

While one embodiment of the present invention has been considered in detail, it will be understood that other embodiments and modifications are contemplated. It is the intention to include all embodiments and modifications as are defined by the appended claims within the of the invention.

What I claim as my invention is:

1. A mobile crane comprising a truck with at least one truck wheel at one end thereof, a crane chassis positioned at the one end of said truck adjacent said wheel, a horizontally oriented first pivot joint connecting the one end of the truck and the crane chassis, said chassis including support means located outwardly of said truck, a crane extending upwardly from chassis, a second pivot joint connecting said crane and chassis located between said support means and said first pivot joint and oriented parallel to said first pivot joint, and a crane support link having one end pivoted to said truck and the other end pivoted to said crane at a point above said chassis whereby rocking of said chassis about said first pivot point moves said crane in a generally vertical direction relative to said truck.

2. A mobile crane as in claim 1 including a power winch mounted on said truck, and a cable wrapped around said winch and secured to said crane at a point above said link whereby rotation of said winch so as to tighten said cable is' operable to move the top of the crane toward the truck and rotate the chassis around the first pivot joint to lift the support means.

3. A mobile crane as in claim 1 including power means operatively secured between said truck and a point on said crane above said link whereby contraction of the powermeans moves the top of the. crane toward the truck and lifts the support means.

4. A mobile crane. as in claim 1 wherein said crane includes a support, a mast telescopically carried by said support, a boom extending outwardly from said mast, and power means for extending said mast relative to said support.

5. A mobile crane as in claim 2 wherein said. crane includes a support, an extendabl'e mast carried by said support, a boom extending outwardly from said mast and lifting means secured to the outer end of said boom, said cable running from said winch, over the top of said mast to said lifting means.

6-. A mobile crane as in claim 1 wherein said link comprises an extendable power cylinder operable to vary the orientation of said crane relative to said truck.

7. A mobile crane as in claim 1 wherein said support means comprises at least one crane wheel aligned to roll in the same direction as said truck wheel and said truck includes drive means for the truck wheels.

8. A mobile crane as in claim 7 wherein said truck wheel and said crane wheel have parallel axes which are separated a distance slightly greater than the sum of the radius of said truck wheel and the radius of said crane wheel.

References Cited UNITED STATES. PATENTS 2,096,186 10/1937 Le Tourneau 2 l28 2,782,939 2/ 1957 Bernaerts 2l2-8 2,956,691 10/1960 Fangman 21235 FOREIGN PATENTS 555,970 2/1957 Italy.

ANDRES H. NIELSEN, Primary Examiner. 

1. A MOBILE CRANE COMPRISING A TRUCK WITH AT LEAST ONE TRUCK WHEEL AT ONE END THEREOF, A CRANE CHASSIS POSITIONED AT THE ONE END OF SAID TRUCK ADJACENT SAID WHEEL, A HORIZONTALLY ORIENTED FIRST PIVOT JOINT CONNECTING THE ONE END OF THE TRUCK AND THE CRANE CHASSIS, SAID CHASSIS INCLUDING SUPPORT MEANS LOCATED OUTWARDLY OF SAID TRUCK, A CRANE EXTENDING UPWARDLY FROM CHASSIS, A SECOND PIVOT JOINT CONNECTING SAID CRANE AND CHASSIS LOCATED BETWEEN SAID SUPPORT MEANS AND SAID FIRST PIVOT JOINT AND ORIENTED PARALLEL TO SAID FIRST PIVOT JOINT, AND A CRANE SUPPORT LINK HAVING ONE END PIVOTED TO SAID TRUCK AND THE OTHER END PIVOTED TO SAID CRANE AT A POINT ABOVE SAID CHASSIS WHEREBY ROCKING OF SAID CHASSIS ABOUT SAID FIRST PIVOT POINT MOVES SAID CRANE IN A GENERALLY VERTICAL DIRECTION RELATIVE TO SAID TRUCK. 